A peptide which is prepared by making protein to small molecules with a hydrolysis is an excellent nutritional ingredient because it is digested and absorbed rapidly. A peptide has attracted attention as a health food or a food for athlete because it is recognized that the peptide has various physiological effects such as higher recovering effect of muscle wasting and effect of promoting muscle strength. As a form for ingesting peptide, drink form is convenient. In fact, a wide variety of beverages such as lactic acid bacteria beverage, tea-based beverage and sports drink are known. Among them, acidic clear beverage has broad utility and is more favorable because it has pleasant sour taste and clear appearance.
However, there is a problem that an acidic clear beverage containing peptide generates cloudiness and precipitation during long-term storage and that a commercial value of the beverage is reduced. As a method for preventing a generation of cloudiness and precipitation in beverage, using emulsifier has been known (patent document 1), but an effect of dissolving precipitate in the method is insufficient. A method of reducing pH has also been known (patent document 2). Although a solubility of peptide is increased in the method, the method has a taste problem that acidic taste becomes too strong. In addition, using a pectin (patent document 3) shows effect of preventing a generation of precipitation, that is, effect of dispersion and stabilization of dreg component, but this method generates cloudiness and is insufficient for clear beverage.